[PATCH 2/2] nvme-multipath: do not select namespaces which are about to be removed

[hch@lst.de (Christoph Hellwig)]

On Wed, Jul 03, 2019@03:12:32PM +0200, Hannes Reinecke wrote:
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index c8cc82639327..1f6105a5c596 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -130,7 +130,8 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
>  
>  	list_for_each_entry_rcu(ns, &head->list, siblings) {
>  		if (ns->ctrl->state != NVME_CTRL_LIVE ||
> -		    test_bit(NVME_NS_ANA_PENDING, &ns->flags))
> +		    test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
> +		    test_bit(NVME_NS_REMOVING, &ns->flags))
>  			continue;
>  
>  		if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
> @@ -180,7 +181,8 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
>  
>  	if (list_is_singular(&head->list)) {
>  		if (old->ctrl->state != NVME_CTRL_LIVE ||
> -		    test_bit(NVME_NS_ANA_PENDING, &old->flags))
> +		    test_bit(NVME_NS_ANA_PENDING, &old->flags)||
> +		    test_bit(NVME_NS_REMOVING, &old->flags))
>  			return NULL;
>  		return old;
>  	}
> @@ -189,7 +191,8 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
>  	     ns != old;
>  	     ns = nvme_next_ns(head, ns)) {
>  		if (ns->ctrl->state != NVME_CTRL_LIVE ||
> -		    test_bit(NVME_NS_ANA_PENDING, &ns->flags))
> +		    test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
> +		    test_bit(NVME_NS_REMOVING, &ns->flags))
>  			continue;

I think we clearly need a patch before the two patches in your
series that factors this check into a little helper with a
descriptive name.  Also doesn't nvme_path_is_optimized also need
to have these checks while we are at it?